Shipping drum unloader



Sept. 2, 1941.. s. s. ROBERTS SHIPPING DRUM UNLOADER 3 Sheets-Sheet 1 Filed July 18, 1939 Sept. 2, 1941. s. s. ROBERTS SHIPPING DRUM UNLOADER Filed July 18, 1939 3 Sheets-Sheet 2 FIG. 2.

H II

fizz/674K071- flaw/051. 5. H

Sept. 2, 1941. s s ROBERTS 2,254,317

SHIPPING DRUM UNLOADER Filed July 18, 1939 3 Sheets-Sheet 3 2! 15 fi A7 0' l6 g a I I 1/ a li a 7 F E 155 /I-/ a A 24 I6 Patented Sept. 2, 1941 UNITED STATES PATENT OFFICE 2,254,317 SHIPPING DRUM UNLOAIlER Samuel S. Roberts, Pittsburgh, Pa.

Application July 18, 1939, Serial No. 285,176

2 Claims.

by the accompanying drawings, inwhich:

Figure 1 is an elevation;

Figure 2 is a vertical section;

Figures 3 and 4 are cross sections taken from the lines III-III and IV-IV, respectively, in Figure 1;

Figure 5 is a vertical section at right angles to the section of Figure2; and,

Figure 6 is a schematic wiring diagram,

the piston in alignment with the drum during reciprocation of the piston.

The columns 5 mount an annular cam i5 having a plurality of inclined surfaces It") supporting a smiling box assembly I6 by way of rollers l1 working on the surfaces Hi and fixed to the assembly l6. These rollers have handles H by means of which the stufling box assembly can be rotated, the rollers l1 riding up and down the surfaces l5 and vertically reciprocating the stufling box assembly.

More specifically, the machine includes a base I I having a central portion 2 formed by a circular recess 3 made in a part of the base I and which accommodates the depending flange of an upright shipping drum 4. These drums are conventionally made with a recessed bottom with their body or cylindrical portion extending therestructure, and a screw 8, the screw engaging a nut 9 fixed inside the sleeve 1 and its bottom being bolted to a piston assembly.

This piston assembly comprises va part Hi to which the bottom of the screw is directly bolted and which connects with the piston proper II by way of tie bolts l2, the part I0 and piston v proper H being urged apart by compression springs Hi. The piston proper H is longer than the drum 4 and has an outside diameter closely I approaching-the inside diameter of the drum, the top of the piston proper connecting with a spider l4 slidably journaled on the sleeve 1 and the upper portions of the columns 5, this keeping It is to be understood that the drum 4 is a con-. ventional type used for carrying lubricant or other plastics, and having a top ferrule, the drum top being removed when it is placed in the machine so that the'piston assembly can enter its interior. The stufling box assembly [6 includes an inwardly extending flange I8 beneath which is a rubber gasket i9 which fits against the top of the drum' flange 4 the assembly l6 including clips 20 which fit against the bottom of the drum flange 4 and these clips being of the cam type operable by handles 2|, operation of these clips serving to compress the gasket l9 against the top ,of the drum flange 4 to form a grease-tight joint. The stufling box assembly includes a packing 22 which works against the side of the piston proper II, this completing the prevention of the leakage of grease past the sideof thepiston proper.

When the sleeve 1 is rotated, the screw 8 effects reciprocation of the piston assembly fixed to its bottom end,-and when this motion'is downwardly toward the bottom of the drum, pressure is applied to the contents inside of the drum, the

springs l3 compressing during this action. Strain of the springs I3 is prevented by stops Ill and H positioned between the relatively moving parts of the piston assembly, these stops intercontacting to prevent undue compression of the springs I3. I

Two of the bolts I2 have tubular bodies l2,

. their bottoms being open to the bottom of the piston proper II and hence to the contents of the drum, and their tops connecting with pipes 23 which extend upwardly to a position slightly below the spider l4 where they are joined to a horizontally extending pipe 24 to which a flexible hose 25 is attached, this hose, having a nozzle 26. It follows that downward movement of the piston assembly applies pressure to the contents of the drum and that these contents are extruded through the nozzle 26. The pipe 24 may, of course, lead directly to the point where the substance extruded from the drum is to be used,

such as, for instance, to the pumps oi a lubricating system when the substance is a lubricant.

Rotation of the sleeve 1 is eflected by a motor 21 driving through a transmission gear set 28 and a worm drive 29, the worm-wheel oi the latter being fixed to the rotative sleeve I. The transmission gear set has a gear shifting lever 28 ,'the motor 21 turning in the same direction at all times and the gears of the transmission gear set 28 being shifted to effect reversal oi the sleeve 1. The ears are so arranged as to turn the sleeve I slowly in the direction effecting downward movement of the screw 8 and more rapidly when rotatedin the opposite direction.

The motor 21 is energized by power lines 30 in which limit switches 3| and 32 are interposed, I

these limit switches beingplaced at the top and bottom of one of the columns 5 and being operable by-a contactor 33 fixed to the spider it which raises and lowers with the piston assembly. These limit switches function to stop the motor 21 when the piston assembly is moved to either of its reciprocatory limits.

A Bourdon tube operated unit 34 is connected by a pipe 35 to the pipe 24, this pipe 35 working through a diaphragm 36 to prevent the entrance of the substance in the drum to the Bourdon tube. This unit 34 contains a switch operated by the Bourdon tube, and this switch is interposed in one of the lines 30 whereby to make the operation of the motor 21 automatically responsive to the pressure exerted on the material in the drum 4 by the piston assembly. Push buttons 3i and 32 serve to energize the motor 21 when either of the limit switches is opened by operation of the contactor 33, these switches being depressed during the time necessary for the motor 2'! to drive the piston assembly to a position where the contactor 33 leaves theswitch it is operating.

Assuming a shipping drum has been placed in the machine and the piston assembly is at its top position, the gear shift lever 28 is thrown to proper position and the button 3| is depressed. Since there is no pressure transmitted through the pipe 24 at this time, the Bourdon tube operated switch unit 34 will provide a closed circuit and the motor 21 will start. As soon as the piston assembly is moved downwardly to a point where the contactor 33 ceases to operate the limit switch 3|, the push button 3i may be released. The motor then continues to operate, the piston assembly entering the drum and exerting pressure on its contents, this compressing the springs l3 of the piston assembly.

The Bourdon tube of the unit 34 is adjusted so as to break the circuit to the motor just prior to the-time the stops Il and iii of the piston assembly would contact. The motor is now deenergized until some of the content of the drum is withdrawn by way of the pipe 24, the springs i3 expanding and maintaining a steady pressure on the content of the drum. As these springs l3 expand, the pressure in the drum drops, the Bourdon tube operated swi h of the unit 34 operating in due course and he motor again driving the piston assembly downwardly until the unit 34 deenerglzes. This continues until all of the content of the drum is driven out. At this time the gear shifting lever 28 is operated to effect a reversing drive at the higher speed of the sleeve 1, the push button switch 32* is depressed a sumcient time interval and the piston assembly rises to its uppermost position. The piston assembly contains a vacuum-breaking device in the form of a check valve 31 which permits the entrance of air between the piston proper and the drum bottom as the piston assembly is withdrawn.

I claim:

1. A machine for unloading a shipping drum containing a plastic substance, including a base having a portion for supporting the bottom of the drum when the latter is placed upright thereon, columns rising from said base outside of said portion, a superstructure supported by the tops of said columns, a rod depending from said superstructure, a piston fitting the drum and mounted by said rod so as'to work in the drum .when the latter is positioned upright with its bottom on said base portion,,and powered means for causing said rod to force said piston downwardly, said columns mounting an annular cam supporting a stuiling box for the top of the drum, said piston being longer than the drum is deep and its side working in said stufling box, the latter being associated with said cam so that relative rotation therebetween eiiects vertical movement of said stufllng box for engagement and release of the latter respecting the drum top.

2. A machine for unloading. a shipping drum containing a plastic substance, including a base having a portion for supporting the bottom of the drum when the latter is placed upright thereon, columns rising from said base outside of said portion, a superstructure supported by the tops of said columns, a rod depending from said superstructure, a piston fitting the drum and mounted by said rodso as to work in the drum when the latter is positioned upright with its bottom on said base portion, and powered means for causing said rod to force said piston downwardly, said columns mounting a stuiling box for the top of the drum, said piston being longer than the drum is deep and its side working in said stufling box, the latter being mounted by said columns by means eiiecting vertical move- SAMUEL s. ROBERTS. 

